A so-called land grid array (LGA) socket is well known. The LGA socket is utilized to mount a LSI chip package on a printed wiring board, for example. The LGA socket includes back-side electrically-conductive terminals arranged on the back surface of a socket substrate. The back-side electrically-conductive terminals are received on electrically-conductive pads on a printed wiring board when the LGA socket is received on the printed wiring board. The LGA socket further includes front-side electrically-conductive terminals arranged on the front surface of the socket substrate. Each of the front-side electrically-conductive terminals are connected to a corresponding one of the back-side electrically-conductive terminals. The front-side electrically-conductive terminals respectively receive the corresponding electrically-conductive terminals of the LSI chip package. In this manner, the LGA socket serves to establish electrical connection between the socket substrate, representative of an electronic component package substrate, and a printed wiring board.    Publication 1: Japanese Patent Application Laid-open No. 59-068187    Publication 2: Japanese Patent No. 2909570    Publication 3: Japanese Patent Application Laid-open No. 8-250242
The socket substrate includes a flange standing upright in the direction normal to the surface of the socket substrate at the outer periphery. The flange is interposed between the printed wiring board and the electronic component package substrate. The socket substrate is equally spaced from the front surface of the printed wiring board and the back surface of the electronic component package substrate. The electrically-conductive pads protrude from the front surface of the printed wiring board by a predetermined height. The electrically-conductive terminals of the LSI chip package sink into the back surface of the LSI chip package. As a result, the back-side electrically-conductive terminals are forced to largely deform as compared with the front-side electrically-conductive terminals. The front-side electrically-conductive terminals enjoy a reduced amount of deformation. A contact pressure is reduced between the front-side electrically-conductive terminals and the electrically-conductive terminals of the LSI chip package. Consequently, a failure in electrical connection is sometimes caused between the front-side electrically-conductive terminals and the electrically-conductive terminals of the LSI chip package.